i am obviously not an expert at unix. can someone please tell me how to change the function of a key on my openbsd setup. The key to increase the backlight turns off the backlight completely. It should be in x11, right? This just happened.

To change the fn + f8 key to increase brightness, wouldn't that be fn_f8=fn_f8? since thats the key on my keyboard? i am confused. What would the proper reference be for that function key and the operation i want it to perform?

The Fn key is typically handled specially by the EC (Embedded controller) in laptops, by itself it usually doesn't generate a keyboard scancode that is detectable by the OS.. but some combinations might.

Brightness control is often done transparently, but if your particular laptop generates a scancode that is usually interpreted by a driver/app running Microsoft Windows you might be able to find a way to simulate the effect using xgamma(1), or perhaps a 3rd party wrapper.. xbrightness.

You can run xev to see if the Fn+F8 key generates anything, if it doesn't, it may be handled by special ACPI events.. which perhaps may be unsupported for your laptop.